1. Field of the Invention
This invention relates to amelioration of salt build-up in earth under cultivation, and more particularly to distributed apparatus and distributive methods for continual, discrete removal of salts from irrigation water. The invention provides generally small, relatively portable, salt removal devices that are not typically fixed to the ground. These salt removal devices employ a solar distillation system of increased efficiency, and concentrate salts recovered in a readily removable and regenerable vessel. The invention method collects salt-bearing water from a source such as irrigating flows over a cultivated area, solar-distills the water, captures the salt in a solar energy-radiated wick structure and returns the desalted water to the field, all with a multiplicity of quite small devices that suitably fit within and among growing crops without any adverse effect on adjacent plant life.
2. Background Art
Water for agricultural use has historically been made available at low cost, providing little incentive to conserve or efficiently use the water. Typically, as in the United States Southwest, water is applied to the cultivated land in abundance and then drained away by gravity as agricultural runoff back into rivers for use and reuse down stream. Limited amounts of water are not applied and allowed to soak in since excess accumulations of salts from the applied water will remain in the soil, making the field unusable for agricultural use for many crops, i.e. all but the most salt tolerant. The saline content of the used and reused water increases with each use and reuse, and field contact adds even more salts, so that the saline content problem cascades and concatenates as the river water flows to the sea, requiring ever greater flooding to minimize salt accumulation and its effects in the soils being irrigated.